Clockwork-escapement for mechanical time-fuses.



H. PRAHL.

CLOCKWORK ESCAPEMENT FOR MECHANICAL TIME FUSES APPLICAT|UN FILED JAN. 2|, I915.

1,21%,068 Patented J zlll. S0, 1917.

WETNEESES- 7 4 I HUGO PRAHL, OF DUSSELDORF, GERMANY.

- CLOCKWORK-ESCAPEMENT FOR MECHANICAL TIME-FUSES.

Specification of Letters Patent.

- Patented Jan. 30, 1917.

Application filed January 21, 1915.; Serial No. 3,583

To all whom it may concern:

Be it known that I, HUGO PRAIIL, engineer, a'subject of the German Emperor, residing at 79 Uerdingerstr'asse, Dusseldorf, Germany, have invented certain new and useful Improvements in Clockwork-Escapements for Mechanical T imc-Fuses; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to improvements in clock work escapcments for mechanical time fuses and has for its object to exclude the influence of the centrifugal force produced by the rotation of the shell on the balance control spring and to enable the balance to swing within a larger arc than it is possible in the known escapements.

The control springs in clock work escapementsof mechanical time fuses are much influenced by the centrifugal force so that many irregularities in the movements of the clock work arise. For avoiding this influence of the centrifugal force I construct my clock work escapement for mechanical time fuses with a straight torsion spring arranged in or in the prolongation of the balance axis. By arranging the clock work within the shell in such a position that the balance axis is inthe axis of rotation of the shell the said control torsion spring is also in the axis of rotation of the shell and therefore not influenced by the centrifugal force.

In the accompanying drawings two embodiments of my invention are shown.

Figure 1 is a side elevation partly in section of a clock work escapementconstructed according to my invention. Fig. 2 is a plan view. Fig. 3 is a side elevation of another embodiment of which Fig. 4 is a plan view. In the modification shown by Figs. 1 and 2 the balance wheel D is'fastened on the shaft 2? pivotally mounted in the plates c and c of the clock work frame. The balance wheel D cooperates in a well known manner with the balance E mounted on the hollow axis f in which by means of a pin in a flat wire it of rectangular cross section is fastened which forms the control spring of the balance. This fiat wire it projects with its upper end into a slot of a bracket Z which by means of screws y can be adjusted in its height with regard to the frameof the clock work. By the adjustment of this bracket Z the operative length of the control spring h is increased or diminished and therefore the clock work runs faster or more slowly respectively. Between the bracket Z and the plate of'theframe in which the-screws g are fastened the spring y' is inserted for excluding any play of the screw due to inaccuracies in the cooperating threads. The ends of the bracket Z are slotted and provided with screws 2' for clamping the bracket Z on to the screws 9 in the desired position.

In the embodiment shown by Figs. 3 and 4 the control spring la, is arranged in the prolongation of the balance axis f and fastened by means of a piece 0 on the end pin of the axis f.

The pin 72. projects into a slot of abrack'et Z" guided on a standard ,4

Z in which it can be adjusted by means of a screw 9. On this screw. the'braeket Z, can be clamped by means of the screw if, and a spring 7' for excluding the play is'provided between an upper leg ofthe standard I and. the projection of the bracket Z" which contains the hole ofthe screw 9'. 7

Having thusdescribed myinvention what I' claim is: Y

1. Ina clock work escapement for meohanical time fuses the combination-of a balance having a hollow shaft and a torsional balance control spring arranged, in said shaft, the axisof rotation" of said balance being coipcident with the axis of rotation of the fuse-when fired.

2. In a clock work escapement for mechanical'time fuses the combination of a balance, a hollow shaft upon which said balance is mounted, a balance control spring 

